Brake block construction



Aug. 2,, 1938. I w. G. SMITH 4 I BRAKE BLOCK CONSTRUCT IO N Filed Dec. 5, 1936 [NVL'NTOR WALTER G. LSM/TH A TTOR/VEK Patented Aug. 2, 1938 I I I UNITED STATES PATENT OFFICE 6 Claims. (01. 188-251) My invention relates to friction brake lining, modates itself to the expansion and contraction and more particularly to the type of lining used of the material of the block. in connection with heavy duty brake shoes for I It is another object of my invention to protrucks, busses, and other types of heavy vehivide, in combination with a brake block, a metal cles, as well as various kinds of stationary mabinding web molded into the body of the block, 5 chinery, such as oil well equipment, etc, the binding web comprising a plurality of helical Brake shoes of vehicles and machinery of the elements disposed de y Side in in r nsae n types indicated above usually are lined with 'frica ns ip and capable of limited relative movetiOn blocks W ich are pro-formed and of rigid ment when the material of the body expands or 10 construction. Brake blocks of this kind are usuntracts t pr v w p of h body- 10 ally formed of molded material and are intended The above objects of the invention will be aD-' to exactly iii; the curvature f th drum engaged parent from the following description in connecthereby, to effect the braking action. Various tion with the accompanyin w s- In the attempts have been made to provide such brake drawing! blocks with reinforcing bases or backing, serv- 1 is Derspective V w Of the brake block 15 me as a foundation binder for the molded maembodying the features of my invention, with terial of the block. One type of base which has a portion thereof broken away t wth metal been used consists in a rigid metal plate having der molded therein. cored portions therein into which the material Fig. 2 is afragmentary section indicating the of the blockis molded under pressure. Another brake block of my invention secured to a brake 20 type of binder used consists of woven metal, such shoe. a 4 as rigid heavy mesh wire screening material, Fig. 3 is a fragmentary face view of the metal which is molded into the base portion of the binding web of my invention, and block. Other types of fabricated metal binding Fig. 4 is a fra men a y end elevation of the have also been used. portion of the web shown in Fig. 3, this view 25 Considerable difliculty has always been encounbeing taken as indicated by e 8 4 O tered in preventing such molded brake blocks Referring to the drawing, I show a rigid, from warping during the curing process thereof. molded brake block II, which according to usual ,The compounded material ordinarily used for practice is preformed to fit the drum which the molding such blocks requires heat curing after outer surface l2 of the block engages in accom- 30 being molded, and the material has a. decided plishing its braking action of the wheels of a tendency to shrink during this curing process. vehicle or other rotating member. According to I have found that the warping of brake blocks usual practice, a series of holes I! are formed during the curing process is due to the relative through the body of the block, the holes i3 being expansion and contraction of the rigid metal countersunk from the braking surface I2 to ac- 5 binder and the material of the blocks. Nodifiicommodate the head of a bolt or rivet, indicated culty is experienced with warping when blocks at l5, which secures the block II to a brake I are molded without rigid metal binding members, shoe IS, a portion of which is shown in Fig. 2. but the binding members are desirable for re- Molded into the body of, the block ll, preferinforcing purposes, particularly to provide supably adjacent the base surface ll thereof so as 40 ports for the rivets or bolt heads which secure to form a foundation for th old d material the blocks t th b k h of the block, is a binder l8.

My primary object of invention is to provide The binder i8 is preferably formed of metal a'metal base or foundation binder, molded inthe wire and is fabricated to form web capable of body of, a brake block metal binder being limited expansion and contraction both longi- 45 capable of limited expansion and contraction to. gg g g gg f gx gfig g 2:; ig g ig g g accommodate to the w and and contraction of the material of the block and traction of the material of the block, so that Wm not tend to war the block h hm k w ning of the block is prevented. p w s n age It is moth b of the material thereof occurs during the cur- 50 er my inventmn Provide ing process to which the block is subjected after a binder for the purpose indicated in the above being ld d, paragraph which consists of mterengagmg The binder web II is preferably formed of a ments capable of limited relative movement in plurality of interengaging elements capable of transverse directions so that the binder accomlimited relativemovement in transverse direc- 5s the web l8, for instance, by crimping the ad'- jacent ends together, as indicated at 22 in Fig.

3. The opposite ends of the elements are preferably free, the crimped ends 22 serving to prevent relative displacement of the elements 20 before the binder is molded into the block.

It will be seen that the construction of the binder web l8 illustrated permits relative movement of the respective elements 20 in transverse directionf that is, it permits relative move ment of the elements inthe directions indicated by the double arrow 25, and also permits relative movement between the elements in the directions indicated by the double arrow 26. Likewise,

material of the block, so that the material has as viewed in Fig. 4, the construction permits limited relative movement between the elements 20 in the transverse directions indicated by the double arrows 21 and 28. The web l8 shown is capable of considerable torsion: that is, the re spective ends 29 and 30 of the web may be relatively twisted in opposite directions in planes perpendicular to the plane of the paper. It will be seen that the preferred; form of fabricating the binder web 'justdescribed permits both longitudinal expansion and contraction of the web in the directions indicated by the arrow 26 of Fig. 3. and transverse expansion and contraction in the directions indicated by the arrow 25 of Fig. 3.

In practice, when the binder web It is molded into the body of the brake block, as by placing the web in the bottom of a mold and compressing the material of the block therein under tremendous pressure, the material of the block is forced into the interstices between the respective elements 20, and the material of the block and the web l8 are formed to a desired contour, such as indicated in Fig. 1. After the brake blocks II are molded, they are subjected to a of the block to any strains either in a longitudinal or transverse direction or to any torsional strain during the normal shrinkage of the no tendency to warp out of shape.

I have shown, for'conveniencein illustration, only one form of fabricated metal webbing for accomplishing the purpose of my invention, but it should be understood that I am aware of various other ,forms of fabricated metal webbing -vision of a metal binder capable of expansion and contraction and capable of sufficient flexibility and torsion so that when such a binder is molded into a brake block thebinder is capable of accommodating itself. to-the expansion or contraction of the material of the block. Therefore, the scope of the invention should be interpreted by the appended claims and not be limited to the illustrative form disclosed in the drawing and described in detail above. I

I claim as my invention:

1. A brake block comprising: a body; and a metal binding web characterized by continuity of metal across one dimension of the web and dis. continuity of metal across the transverse dimen- 'sion,-said web consisting of separate elements having loosely intermeshing portions capable of limited relative movement allowing longitudinal and transverse expansion and contraction of said web, said web being molded in said body whereby relative shrinkage of the: material of said body and the metal of said binding web will not warp said body.

'2. A brake block comprising: a body; and a metal binding web molded in said body, said web being characterized by continuity of a metal across one dimension of the web and discontinuity of metal across the transverse dimension, and consisting of individual intermeshing elements capable of limited relative movement, the web being capable of torsion whereby relative expansion and contraction of the materials of said body and said web will not warp said body.

3. A brake block comprising: a pre-formed molded body; and a metal binder molded therein characterized by continuity of metal in one direction and discontinuity of metal in the transverse direction and consisting of a plurality of elements having loosely interengaging portions capable of limited relative movement whereby expansion and contraction of the material of said body relative to said binder will not warp said body.

4. In a brake block of the character described, the combination of a body of brake lining material; anda metal binding web imbedded therein, said web comprising a plurality of helical elements disposed side by side in intercngaging rela tionship and capable of limited relative movement when the material of said body expands or contracts to prevent warping of said body.

5. In a brake block of the character described, the combination of: a body of brake'lining material; and a series of individual, sinuously de-' formed, flexible reinforcing members embedded in said body in side-by-side disposition with loops .of adjacent members of said series loosely passing through each other.

6. In a brake block of the character described, the combination of a body of brake lining material; and a metal'reinforcing web embedded in said body; said web being characterized by continuity of metal across one dimension and discontinuity across the transverse dimension and comprising flexible metal strands, said strands being sinuous in form for longitudinal extension and contraction in the dimension of continuous metal across the web and being interconnected loosely to permit movement relative to each other in the transverse direction across the web.

WALTER G. L. SMITH. 

